Southern California screenin’

By |  October 23, 2013

Chandler’s Sand & Gravel’s quarrying roots in Southern California stretch back nearly 80 years, but the company as it’s structured today is very much one that leans on recycling and land reclamation as its backbone.

Since 2004, when Inert Debris Engineered Fill Operations (IDEFO) were recognized in California,

Chandler’s Sand & Gravel relies on a QE440 scalping screen from Sandvik to handle mixed loads such as concrete-asphalt. So far, Vice President Trevor Wood says the Sandvik unit is “blowing through” the operation’s material.

Chandler’s Sand & Gravel relies on a QE440 scalping screen from Sandvik to handle mixed loads such as concrete-asphalt. So far, Vice President Trevor Wood says the Sandvik unit is “blowing through” the operation’s material.

Chandler’s Sand & Gravel’s business has shifted. The operation continues to own and lease out quarries in Corona, Calif., including a newly acquired Cemex pit.

But Trevor Wood, the company’s vice president who’s part of the fourth generation of Chandlers involved in the family business, says a significant portion of revenue is now generated from construction materials that are recycled at a 67-acre active site in Palos Verdes, Calif.

“We are in such an environmentally conscious state,” Wood says. “Our industry is still developing, but in essence we are reclaiming existing operations to make more reusable land. We are trying to preserve California’s minerals and resources. We see opportunities to recycle something others are destroying, and in everything we do we want to take the land and build it back up.”

Chandler’s accepts a variety of products, including asphalt, concrete and dirt in Palos Verdes. Some materials are used in the operation’s recycling processes and sold as construction aggregates, including asphalt grindings, screened sand and crushed miscellaneous base. Other materials, such as brick and porcelain, are taken, laid down and compacted.

Operation breakdown
In all, Chandler’s Sand & Gravel breaks its IDEFO down into five key areas: landfill; clean dirt; clean crushables; concrete-asphalt; and clean concrete. Chandler’s relies on two portable plants to create these various products, including an R155 screener from McCloskey International Ltd. and a QE440 scalping screen from Sandvik.

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For a few years, a tracked R155 screener from McCloskey processed the materials the operation’s QE440 scalping screen currently does. Now, Chandler’s Sand & Gravel uses the R155 primarily to screen sand.

“We recently replaced McCloskey’s R155 with a QE440,” Wood says. “We just got the QE440 in 2012, and it’s being used for all of our mixed loads like concrete-asphalt and dirt,” Wood says. The McCloskey unit held up pretty well for a few years, but it’s better at handling our sand.

“This Sandvik unit just blows through our material. We used to always have a stockpile with the McCloskey (R155). With the Sandvik (QE440), we never have a stockpile.”

Wood estimates that the QE440 processes about 200 tph for Chandler’s, but he says it’s capable of processing at an even higher rate.

“Because of the size of the material we put through, we don’t want to push it,” Wood says. “I don’t doubt that it can handle more, but as it is it’s keeping up with us.”

For Chandler’s, one key to increasing the QE440 scalping screen’s durability was reinforcing it with a 1/2-in. steel plate on the hopper because of the operation’s loader.

“Pieces can be large in size when we feed,” Wood says. “We just want to preserve it. We did that with the McCloskey (R155), as well. It’s a lot easier to replace 1/2-in. steel than to replace a whole side of a hopper when it comes to our asphalt and concrete recycling.”

Meanwhile, one key material Chandler’s R155 screener produces is a screened sand that comes from stockpiled material it receives. Wood describes the unscreened material, similar to an

For a few years, a tracked R155 screener from McCloskey processed the materials the operation’s QE440 scalping screen currently does. Now, Chandler’s Sand & Gravel uses the R155 primarily to screen sand.

For a few years, a tracked R155 screener from McCloskey processed the materials the operation’s QE440 scalping screen currently does. Now, Chandler’s Sand & Gravel uses the R155 primarily to screen sand.

SC30 that Chandler’s also sells, as having some clay in it. But once screened, a finer sand product is produced.

In addition to the McCloskey and Sandvik portable units, Chandler also rotates a QI340 impact crusher from Sandvik between a quarry and its recycling yards.

“That thing’s been pretty good so far,” Wood says. “On average, it puts out about 200 tph for us. If the concrete is not sized properly, it will slow the machine down a little bit. But we’re in the process of buying a jaw crusher to go along with it.”

Realizing new opportunity
According to Wood, Chandler’s Sand & Gravel started in 1934 as a mining company. A property in Corona, Calif., was purchased in 1975, and the operation mined there from about 1976 to 1995.

But it was around 1995, Wood says, that his grandfather died, his uncle took over operations and the outlook for the business shifted. Chandler’s leased out its mining operation around that time, and it focused more intently on land reclamation and recycling opportunities.

“We’ve geared down to strictly reclaiming the land,” Wood says. “We’re trying to get away from the word ‘landfill.’ We’re really not one because we recycle so much, and so much of the material is clean. So the words ‘land reclamation’ are something we’re trying to get out there.”

As a state, Wood says California isn’t necessarily at the forefront of recognizing operations like Chandler’s as the recyclers they truly are. But the mindset is changing.

“We’re growing as a state and we’re growing as an industry when it comes to recognizing possibilities and the recycling possibilities of our industry,” Wood says.

One premium example of the results that can be had from efforts like Chandler’s is what’s in store for a portion of the IDEFO site. According to Wood, the site is already approved for an 18-hole Arnold Palmer-designed golf course, a 50,000-sq.-ft. country club and 114 luxury homes.

Chandler’s five business units

Chandler’s Sand and Gravel’s Inert Debris Engineered Fill Operation in Palos Verdes, Calif., is broken down into five key areas:

A look at some of the processed materials at Chandler’s Sand & Gravel in Palos Verdes, Calif. A crushable concrete-asphalt pile is at the far left, while a Class 2 clean concrete base product is piled beyond the wheel loader. The third pile, at right, contains a Class 2 crushed miscellaneous base product.

A look at some of the processed materials at Chandler’s Sand & Gravel in Palos Verdes, Calif. A crushable concrete-asphalt pile is at the far left, while a Class 2 clean concrete base product is piled beyond the wheel loader. The third pile, at right, contains a Class 2 crushed miscellaneous base product.

1. Landfill. All non-recycled products, including brick and porcelain, are compacted as part of an ongoing reclamation project.

2. Clean dirt. This is all stockpiled for cover. Vice President Trevor Wood says the operation still needs about 1 million tons of clean dirt for its reclamation purposes.

3. Clean crushables. Represents some material processed in Chandler’s fourth area.

4. Concrete-asphalt combination. Municipalities are the primary source of this material. Chandler’s screens this and takes it to the third area.

5. Clean concrete. This is an area Chandler’s opened about one year ago.
“We’re stockpiling clean concrete,” Wood says. “We’re finding a lot of municipalities and school districts don’t approve of CMB (crushed miscellaneous base). The asphalt concerns them near water tables, so they always go to natural [aggregate] base.”

As an alternative, Chandler’s is creating a natural concrete base. Wood says school districts are finding it to be a suitable product.

“Here in California, it’s in the very beginning stages,” he says. “We already have a few orders of about 50,000 tons coming up.”

Another area Chandler’s is exploring is recycled asphalt shingles, which Wood sees as a market that has some possibilities. Still, Wood believes more research needs to be done before Chandler’s makes a serious commitment to them.

“There’s not a lot of research being done to find out if shredding them makes the oil content better,” he says. “The process of shredding is very costly and requires lots of maintenance. Machines are expensive, and every day of maintenance is expensive.

“What you’re finding are a lot of commercial-grade asphalt shingles in which the petroleum percentage is at about 20 percent. That will save [customers] money versus buying gas or petroleum oil. It’s a blend, just like using RAP (reclaimed asphalt pavement). We currently screen asphalt grindings for reuse for dust-control purposes and yard roads.”

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